Scalpellidae Pilsbry 1907

Scalpellidae is a family of acorn barnacles in the order Scalpellomorpha. There are about 25 genera and 220 described species in Scalpellidae.

Tentative attempts to subdivide Scalpellum into groups and subgenera were begun by Pilsbry (1907) and Hoek (1907), who both used the form of the carina and the morphology of the dwarf males to characterize a number of subgenera and groups (for an exhaustive review, see Young, 1999). The genera were discussed by Withers (1953), who synonymized extensively, and the Treatise on Invertebrate & Withers, 1969) included just three genera in the family, which would now be considered as scalpellids: Scalpellum, Mesoscalpellum Hoek, 1907, and Arcoscalpellum Hoek, 1907. The next decade saw a great proliferation of scalpellid genera: in a taxonomic account of the Antarctic cirripedes, Newman & Ross (1971) created seven new genera, and Zevina (1978a,b) added a further 22 genera, classified into eight subfamilies. Subsequently, Newman (1996) elevated three of these subfamilies to family status (Calanticidae, Lithotryidae, and Pollicipedidae), leaving eight subfamilies and 29 genera for the scalpellids. The proliferation of new genera was commented on by Foster (1980: 523), ‘The Scalpellidae have recently been reclassified by Zevina (1978a,b), who built on an earlier proposal by Newman & Ross (1971), but the classification is still more convenient than natural’. Young (1999: 186) subsequently applied cladistic analysis to the genera in order to assess the monophyly of subfamilies. He commented that, ‘The characters used for supra-specific taxonomy are homoplastic, therefore forming paraphyletic subfamilies’. He also noted that the basal group Arcoscalpellinae and its constituent genera were probably paraphyletic, citing Trianguloscalpellum as an example (Young, 1998, 1999); however, Young’s 2007 review of extant scalpellids followed Zevina’s generic classification in detail, although he commented on the significance of growth dependent features in scalpellid classification, which had not been taken into account in previous studies. In his papers on scalpellids, Paulo Young seldom provided generic diagnoses, an exception being Amigdoscalpellum (Young, 2007: 59). A subsequent paper by Shalaeva & Boxshall (2014) refigured Hoek’s Challenger scalpellids (Hoek, 1883), provided revised generic diagnoses based on the translation of Zevina’s original descriptions, and summarized points of discussion made by Young (notably the 1998 and 2007 papers).A paper on the molecular phylogeny of Antarctic scalpellomorph cirripedes (Linse et al., 2013) implied the paraphyly of species assigned to Arcoscalpellum. The most recent molecular phylogenetic analysis of Salpellids is by Lin et al. 2015 which revealed Scalpellids forms two monophyletic clades (A and B). Gale (2015) reviewed the Scalpellids and match the morphology into these two clades and divided Scalpellidae into two subfamiles Scalpellinae and Amidgoscalpellinae. Lin 2015 and Gale 2015 is cited in WoRMS page here. The present WoRMS follow Lin et al. 2015 and Gale 2015 for the taxonomic classification of Scalpellidae.